Ice north of Greenland perhaps missing the larger MYI component this year.
a closer view with a bit less cloud
Uniquorn, I wonder why the cracks are not visible on this DMI sentinel image taken the same day ?
Good idea, we could learn a lot from more comparisons of radar and brightness temperature images
Sentinel-1 is the first of the Copernicus Programme satellite constellation conducted by the European Space Agency.[4] This mission is composed of a constellation of two satellites, Sentinel-1A and Sentinel-1B, which share the same orbital plane. They carry a C-band synthetic-aperture radar instrument which provides a collection of data in all-weather, day or night. This instrument has a spatial resolution of down to 5 m and a swath of up to 400 km. The constellation is on a sun synchronous, near-polar (98.18°) orbit. The orbit has a 12-day repeat cycle and completes 175 orbits per cycle.
Brightness Temperature (Band I5, Night)
Temporal coverage: 17 September 2017 - Present
The VIIRS Brightness Temperature, Band I5 Night layer is the brightness temperature, measured in Kelvin (K), calculated from the top-of-the-atmosphere radiances. It does not provide an accurate temperature of either clouds nor the land surface, but it does show relative temperature differences which can be used to distinguish features both in clouds and over clear land. It can be used to distinguish land, sea ice, and open water over the polar regions during winter (in cloudless areas).
The VIIRS Brightness Temperature layer is calculated from VIIRS Calibrated Radiances (VNP02) and is available from the joint NASA/NOAA Suomi National Polar orbiting Partnership (Suomi NPP) satellite. The sensor resolution is 375m, the imagery resolution is 250m, and the temporal resolution is daily.
My layman interpretation is that Sentinel-1 is showing ice surface features picked up by reflected radar while VIIRS Brightness Temperature(Band 15) is showing temperature difference, in this case mostly that escaping from the ocean beneath the ice, for example, old leads in various thicknesses of refreeze.
A basic overlay is a useful start for further interpretation despite the huge difference in resolution. Large older floes are clearly identified amongst the younger refreeze by brightness temperature with radar showing their intricate surface features.
Brightness temperature scale ~200%, Sentinel-1 scale ~20%. Both images have been contrast adjusted to clarify the overlay. Different palettes might reveal more.click for overlays
Thinking about it, it's possible that leads may be exaggerated somewhat by brightness temp detection from space. It is very good for showing ice dynamics during winter though. In summer the temperature diff is much less.
